Not sure exactly where they shaved the weight of the STR60 vs the ST60 calipers but according to the web site there is a 20% reduction of mass. I would assume there to be some difference in shape.
With the 15mm spacers the stock 18's are still tucked up under pretty well with 255 AD08's. I get some light rubbing of the fender liner at full streering lock but nothing major. The rubbing started with the 255 AD08's though. I don't have many pics at a side profile but here's one that I have on my phone.